This invention relates to so-called floor sweeping compounds, products that are broadly notoriously old. Such compounds ("compositions" might seem a more appropriate term) traditionally contain a blend of sawdust, sand, and a dust-absorbing liquid (typically petroleum oil); these compounds also generally include a preservative and, for aesthetic purposes, a dye. Handfuls of floor sweeping compound are broadcast over the area to be swept; after sweeping has been completed, the dust-laden compound is discarded in a sanitary landfill.
Many environmentally conscious states have recently passed laws forbidding the disposal of petroleum products in landfills. In an attempt to comply with such laws, applicant's assignee developed a sweeping compound in which petroleum oil was replaced with biodegradable acid oils derived from vegetable acid oils, e.g., soybean acid oil; see U.S. Pat. No. 5,286,399. While this product has enjoyed modest commercial success, it is more expensive than petroleum oil and does not age especially well.
It has long been recognized that replacing the oil in sweeping compounds with water would not only reduce cost but also provide a more environmentally acceptable product, with no oily residue remaining on the floor after sweeping. The rapid evaporation of water, coupled with its inability to impart long term stability and dust absorbing properties, has made such products difficult to use and resulted in limited commercial acceptance. For example, prior art water-based sweeping compounds can not be broadcast over an entire floor area, but must be spread in a line and quickly swept up.
Attempts have been made to remedy the deficiencies of water-based sweeping compounds by incorporating glycerin (U.S. Pat. No. 939,369), to which may be added hygroscopic calcium chloride (U.S. Pat. No. 1,057,923), but none of these products has proved commercially acceptable. Glycerin, for example, is both sweet and viscous, tending to attract pests and to remain on the floor after sweeping; further, its use adds significantly to the cost. Calcium chloride is a corrosive and deliquescent substance that not only is unpleasant to handle but also could corrode metals with which it comes in contact. Further, its ability to retard the evaporation of water is directly related to the humidity of the environment, and it is unreliable as a means of retaining moisture and yielding a consistent product.